1. HERD Prototype Beam Test
PMT Trigger System and Data
Tianwei Bao（鲍天威）
Institute of High Energy Physics, CAS

2. PMT Trigger System Characteristics
Functions：
Self-trigger generation and PS-trigger distribution
Supplementary energy measurement
Beam status monitor：real-time histogram and count rate
Timestamp synchronization with ICCD by PPS

3. PMT Trigger System Characteristics
Performance：
Dynamic Range：69dB
4 individual channels
Trigger delay：6ns
DAQ ：80MSPS×12bit
Dead time：500ns

4. PMT Trigger System-Coupling of Fiber and PMT

5. Setup for the Beam Test Instrument Configuration：4 individual channels
C24 cell->Trigger Fiber->PMT Anode
C24 cell->Trigger Fiber->PMT Dynode
249 cells->Trigger Fiber->PMT Anode
249 cells->Trigger Fiber->PMT Dynode
High
Trigger
Low

6. PMT Trigger System-PMT Driver and Pre-amplifier

7. PMT Trigger System-Hardware and Firmware

8. PMT Trigger System-DAQ and Monitor Software

9. Energy Measurement
100 GeV e-, 249 cells, PMT and ICCD histogram comparison
Histogram comparison
Synchronization by the trigger serial number

10. Energy Measurement e-, 249 cells: PMT DYNODE vs ICCD
50GeV e-
100GeV e-
Matched by the same trigger serial number
Linearity could be derived from the low energy part
150GeV e-

11. Energy Measurement e-, 249 cells: PMT ANODE vs ICCD
50GeV e-
100GeV e-
Saturation observed
PMT high voltage was not set properly in the beam test
150GeV e-

12. Energy Measurement e- C24 cell, PMT DYNODE vs ICCD Deviation is large
100GeV e-
200GeV e-
Deviation is large
Detection for 1 cell is not sensitive enough
150GeV e-

13. Energy Measurement 249 cells, preliminary calibration 249 cells
Calibration by ICCD data
Resolution : 90GeV

14. Energy Measurement the C24 cell, preliminary calibration
Deviation is very large
Calibration by ICCD data

15. Energy Measurement Total 250 cells, preliminary calibration
Merge calibrated PMT data from the 249 cells and the C24 cell
Resolution is dependent on the deviation of C24

16. Self-Trigger Generation
Delay between PS trigger and PMT self-trigger, 100 GeV e-

17. Summary Proved functions： Work in the future：
Trigger generation and distribution
Basic energy measurement
Beam status monitoring
Synchronization with ICCD by PPS
Work in the future：
Fixing the saturation issue
Optimize the electronics to enlarge the dynamic range
Noise reduction to detect the pion deposition

18. Thank you！ Tianwei Bao（鲍天威） baotw@ihep.ac.cn
Institute of High Energy Physics, CAS

19. Energy Measurement 50 GeV electrons vs 50 GeV positrons 50GeV e-

20. Energy Measurement Total 250 cells preliminary calibration
Merge calibrated data from the 249 cells and the C24 cell
Resolution is not reliable for the deviation of C24